My boss always listens first to whatever that I want to talk about with her.
For this, I can really trust and rely on her.
ご質問ありがとうございます。
"My boss always listens first to whatever that I want to talk about with her."=「私の上司はいつも、まず私が彼女と話したいことを聞いてくれます。」
"For this, I can really trust and rely on her."=「なので、私は彼女をとても信頼し、頼りにしています。」
ご参考までに。